A Tweet is any message posted to Twitter which may contain photos, videos, links and up to 140 characters of text.
Promoted Tweets are ordinary Tweets purchased by advertisers who want to reach a wider group of users or to spark engagement from their existing followers. Promoted Tweets are clearly labeled as Promoted when an advertiser is paying for their placement on Twitter. In every other respect, Promoted Tweets act just like regular Tweets and can be retweeted, replied to, liked and more.
Promoted-only Tweets are Promoted Tweets that are only shown to users targeted in your advertising campaigns. Unless specifically targeted, Promoted Tweets do not show on your followers’ timelines. When seen by a targeted user, they act like normal Tweets and can and can be retweeted, replied to, liked and more.